Screw-thread protector



J. SCHIRRA.

SCREW THREAD PROTECTOR.

APPLICATION FILED OCT. 10, 1919 Patented Aug. 17, 1920.

JULIUS SCHIRRA, 0F PITTSBURGH, PENNSYLVANIA, 'ASSIGNOIR TO BROWN SPECIAL- TIES COMPANY, .OF PITTSBURGH, PENNSYLVANIA. Y

SCREW-THREAD PROTECTOR.

Specification of Letters Patent.

Patented Aug. 17, 192(1).

Application filed October 10, 1919. Serial No. 329,707.

To all whom it may concern:

Be it known that l, JULIUs SoHIRRA, a citizen of the United States, residing at Pittsburgh, in the countyof Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Screw- Thread Protectors and I do declare the following to be a full, clear, and exact description of the invention, such as .will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to thread protectors, and it relates more specifically to certain improvements upon somewhat similar devices disclosed in my prior Patents Nos.-

' tion to the external threads of a pipe, rod,

bolt, screw or the like, and will not accidentallv become dismembered'or disengaged from the threads on which it is seated, and which will not be detrimentaily affected by moisture so as to destroy or lessen its efficiency.

Other objects and advantages may become apparent to persons who read the following details of description in connection with the accompanying drawings, in which:

Figure 1 is a side elevation of my improved thread protector applied to a threaded end of a fragment of pipe.

Fig. 2 is an enlarged fragmentary detail view showing my improved thread protector partly in central section and partly in side elevation, this view also showin the relation of the thread protector to tie threads.

Fig. 3 is a sectional view, the section being taken substantially on the line 3-3 of Fi 1.

fiig. 4 is a perspective view illustrating the metal band detached from the nonmetallic sleeve which it normally surrounds.

Fig. 5{ is a modified form in which the fibrous or non-metallic sleeve is extended in opposite directions from the metal band.

ig. 6 is a detail view illustratmg another modified form.

Referring to these drawings in detail, in

which similar reference characters correspond with similar parts throughout the several vlews, and in which the pipe section 1 is disclosed merely to illustrate the use of the invention, this pipe section being formed with screw threads 2 l The invention consists mainly in th special construction and arrangement of the fibrous or non-metallic sleeves 3 and 3* and the metallic strips or hands 4 and 4:. The non-metallic sleeve 3 is provided with two annular beads 5 and 6, the latter having a substantially frusto-conical extension or protecting flange 7. The sleeves 3 and 3 are formed with overlapping ends to form a loose joint as indicated at 8, and therefore, the ends of the sleeve which project beyond the band 4 are easily expanded to a limited extent for permitting the front end of the sleeve to be very easily started over the threaded end of the pipe or other threaded member. However, the band 4:, being of metal, is less easily expanded, although it permits of a limited and restricted expansion by reason of a series of corrugations 9 formed in one side. This band is of springy material, and constantly tends to resume its re-. tracted position, thereby pressing the non-- metallic sleeve into intimate engagement with the threads'Q, so that the crests of the threads are sufiiciently embedded in the nonmetallic sleeve to prevent its accidental dis engagement from the threads. Moreover, this elasticity and expansibility of the band compensates for slight variations in diameters of screw threads, and also compensates for variations of thickness of the sheet material from which the sleeves are formed. The band 4 is provided with sharp edges 10 which tend to/cut into the adjacent surfaces of the annular-beads and prevent accidental removal of the band from the cylindrical space between the beads.

In order that the metal band may not rotate about the sleeve, and may be used as an aid in turning the sleeve onto the screw threads, tongues 11 may be formed in the metallic band and pressed into locking engagement with the non-metallic sleeve, as more clearly shown in Fig. 3.

Althou h the metallic band may be endless, it is ere illustrated as having interlapping and interlocking ends 12, each of these ends being p ovided with a laterally-opening notch, so hat the ends 12 may be hooked As a modification of the manner of securing the band to the non-metallic sleeve, the latter may be formed with a slot through which the ends 12 extend (see Fig. 6), and these ends may be bentin opposite directions to form hooks. This not only secures the ends of the band against or adjacent to one another, but prevents the band from becom ing disengaged from the sleeve.

in the modified form illustrated in Fig. 5, three of the heads 5 are illustrated, and the band lis disposed between the two intermediate beads 5. The beads 5 and 6 not only secure the metallic band in place, but add strength and rigidity to the sleeves so that they retain. their shape when not secured on the screw threads.

From the foregoing description, it will be seen hat the present invention overcomes certain disadvantages encountered in the derotected by the above mentioned pato device disclosed in Patent 600,892,

-n1etallic sleeve is not supported by a 1 ii T;

sleeve oecoines wet or damp,'it expands and was overcome by my Patent No.

a another disadvantage was encounter in consequence of the metallic fien ing the entire length of the ieeve would s that the ends of the s permit screw ed into sleeve, involvccnsiderable loss of time, and also involv' a very considerable waste of a eought overcome the foreies by the disclosed 1,303,402, is, dispensing and and reinforcing the nonsleeve doubling a portion. of the mate 'al of which the sleeve was formed. s construction also proved un c band, and therefore, when this screw threads. 'fhis disad=- intense withstand moisture, and would become disengaged from the screw threads. Moreover, returning again to Patent 636,566, it was necessary to provide an annular series of spurs a for preventing accidental separation of the metal band and non-metallic sleeve, as resulting in an unnecessary expense of time in assembling the device.

In the present invention, it is found that the sharp edges 10 effectively prevent separation of the band from the sleeve, and that 55 the relatively narrow strip or band is very eificient while eliminating the disadvantages pointed out with regard to the prior patents.

Although these embodiments of the invention are described very specifically, it is not intended to limit the invention to these exact details of construction, but changes may be made within the scope of the inventive ideas as implied and claimed.

W hat ll claim as my invention is: {it

1. In a screw-thread protector, a nonmetallic sleeve having open ends and havii spaced annular beads therearound, and a metal band embracing the part of the sle between said beads and having sharp to engage with said beads for preven" ng ccidental removal of the metal band from the space between the beads.

2; in a screw-thread protector, a nonmetallio sleeve having open ends and hav spaced annular beads therearound, metal band embracing the part of the s between said beads and having sharp e to .engage with said heads for prev accidental removal of the metal band "frolic so the space between the beads, said metal band being elastic and errpansible to compensate for variations in size to press the sleeve into binding engagement with the being protected thereby. W

In testimony whereof I have hereunto set my d ULKUS 

